It is NOT a good cheap Ca source to make anything!
I don't understand where these idea's come from.....The amounts of minerals found in molasses are so low that once you put your tsp to TBL of molasses to a gallon of water....The amounts available TO the plant are so low that they have no measurable effect to plant growth!. They are trace amounts at best! In all reality, N would be the most available in the pure molasses form (right out of the bottle) at 0.40 average % by volume.......Now how low do you think that becomes in your feed concentration by using even 1 TBL of molasses in a gallon of feed mix? Keep in mind the amounts by volume percentage of the other things like Ca, P, K, Ir, S, etc, etc are well lower then the N value!
Are you seeing the truth yet!
But of course, If it makes you feel good - use it !!!!!
It's sure not hurting anything!